1. Field of the Invention
The present invention relates to chained terminals and to a method for forming or producing such chained terminals.
2. Description of the Related Art
Terminal fittings are produced from a long metal plate that is stamped out by a press such that a multitude of terminal fitting pieces project from a lateral edge of a narrow carrier. The terminal fitting pieces are bent to have a form specified for the terminal fittings, thereby obtaining chained terminals. The chained terminals are wound around a reel and transported to sites for separating the terminal fittings from the carrier and connecting the terminal fittings to a printed circuit board. A prior art construction for winding the chained terminals around a reel is disclosed in Japanese Unexamined Utility Model Publication No. 5-8894 and other publications.
A long strip of interlayer sheet is applied to radially inner surfaces of the prior art chained terminals when the chained terminals are wound around the reel. Thus the chained terminals are wound around the reel together with the interlayer sheet. The interlayer sheet prevents the chained terminals from touching the chained terminals located in the adjacent wound layer and prevents them from being scratched, entangled and damaged due to their mutual interference.
FIG. 9 shows one piece of prior art chained terminals xe2x80x9caxe2x80x9d to be connected to a printed circuit board. The prior art chained terminals xe2x80x9caxe2x80x9d include a plurality of terminal fitting pieces, one of which is shown in FIG. 9 and is identified as xe2x80x9cbxe2x80x9d. The terminal fitting piece xe2x80x9cbxe2x80x9d includes connection portions xe2x80x9ccxe2x80x9d in the form of pins that project outwardly. The terminal fitting piece xe2x80x9cbxe2x80x9d (terminal fitting), when separated from its carrier xe2x80x9cdxe2x80x9d, is mounted on a printed circuit board (not shown) by inserting the connection portions xe2x80x9ccxe2x80x9d into through holes of the printed circuit board and soldering them. The chained terminals xe2x80x9caxe2x80x9d also are wound around a reel xe2x80x9cfxe2x80x9d together with an interlayer sheet xe2x80x9cexe2x80x9d during transportation, and are dispensed from the reel xe2x80x9cfxe2x80x9d together with the interlayer sheet xe2x80x9cexe2x80x9d at a transportation end.
The prior art chained terminals xe2x80x9caxe2x80x9d are wound as shown in FIGS. 7 and 8, such that the connection portions xe2x80x9ccxe2x80x9d project radially outwardly, and such that the projecting ends of the connection portions xe2x80x9ccxe2x80x9d of the terminal fitting pieces xe2x80x9cbxe2x80x9d are in contact with the interlayer sheet xe2x80x9cexe2x80x9d at a radially outer side. The interlayer sheet xe2x80x9cexe2x80x9d is made hard to tear by, for example, selecting a suitable material therefor or applying a surface treatment. However, if a tension acting on the chained terminals xe2x80x9caxe2x80x9d increases during the winding, or if the reel having the chained terminals wound therearound is subjected to large vibration during transportation, the leading ends of the connection portions xe2x80x9ccxe2x80x9d at the radially inner side may stick into the interlayer sheet xe2x80x9ccxe2x80x9d at the radially outer side. If the chained terminals xe2x80x9caxe2x80x9d are dispensed from the reel xe2x80x9cfxe2x80x9d with the connection portions xe2x80x9ccxe2x80x9d stuck into the interlayer sheet xe2x80x9cexe2x80x9d, the stuck portion of the interlayer sheet xe2x80x9cexe2x80x9d catches the connection portions xe2x80x9ccxe2x80x9d when departing from the reel xe2x80x9cfxe2x80x9d. At this time, the interlayer sheet xe2x80x9cexe2x80x9d may deform the caught connection portions xe2x80x9ccxe2x80x9d since the interlayer sheet is hard to tear.
An easy-tear interlayer sheet may be considered to prevent the deformation of the connection portions xe2x80x9ccxe2x80x9d. However, an easy-tear interlayer sheet xe2x80x9cexe2x80x9d cannot fulfill its original function of avoiding a direct contact of the chained terminals xe2x80x9caxe2x80x9d. Conversely, it may be considered to increase a tear strength by thickening the interlayer sheet xe2x80x9cexe2x80x9d. However, since the interlayer sheet xe2x80x9cexe2x80x9d is made of paper, it is difficult to prevent it from being torn by the metal connection portions xe2x80x9ccxe2x80x9d. An improvement in the tear strength of the interlayer sheet xe2x80x9cexe2x80x9d by applying surface treatment or changing a material is not desirable since it results in an increased cost.
In view of the above problems, an object of the present invention is to provide chained terminals and a method for producing the chained terminals that allows for an improved operability, in particularly preventing projections of terminal fitting pieces from being caught in by an interlayer sheet and defined.
According to the invention, there are provided a chained terminal array with a multitude of terminal fitting pieces connected with or extending from a lateral edge of a long carrier preferably a strip or plate. The terminal fitting pieces each have connection projections that project therefrom for connecting the terminal fitting pieces to an external device. The terminal fitting pieces are connected with the carrier in such an orientation that the connection projections thereof project in directions substantially parallel to or substantially lying in the plane of the carrier.
Accordingly, the connection projections do not extend away from the plane of the carrier, thereby reducing the likelihood of interference of the connection projection with outside parts, such as a layer of terminals placed on the upper or lower part thereof or such as an interlayer sheet arranged thereon.
According to the invention, there is further provided a chained terminal array with a multitude of terminal fitting pieces connected with or extending from a lateral edge of a carrier. The carrier preferably is in the form of a long strip or plate, and is formed with one or more protecting portions that project from the carrier in a direction at an angle different from 0xc2x0 and 180xc2x0, and preferably substantially normal to the carrier. A projecting distance of the protecting portions in a direction normal to the plane of the carrier is substantially larger than a projecting distance of the corresponding or adjacent terminal fitting piece. Accordingly, the protecting portions can be held in contact with an interlayer sheet e.g. on the radially outer side. Thus the projecting portions enable intervals between the respective layers of the chained terminals to be larger than the radially outwardly projecting distance of the terminal fitting pieces, thereby preventing the terminal fitting pieces from contacting the interlayer sheet laid adjacent thereto.
Preferably, distal ends of the protecting portions are bent so that the protecting portions substantially have an L-shaped cross section.
Most preferably, the chained terminals are wound or windable around and dispensed or dispensable from a reel with an interlayer sheet laid between adjacent layers of the chained terminals. The terminal fitting pieces are connected with the carrier such that the connection projections thereof project in directions substantially normal to radial directions of the reel.
According to a further preferred embodiment of the invention, there are provided chained terminals which are constructed such that a multitude of terminal fitting pieces are parallel to one another and extend from a lateral edge of a long carrier strip. The chained terminals are wound around and dispensed from a reel with an interlayer sheet between adjacent layers of the chained terminals. The terminal fitting pieces are formed with projections that project normal to radial directions of the reel.
With the chained terminals wound around the reel, the interlayer sheet is laid between the terminal fitting pieces in a radially inner layer and those in the radially outer layer. Since the projections of the terminal fitting pieces project in directions normal to the radial directions of the reel, i.e. directions substantially along the plane of the interlayer sheet, the projections do not stick into the interlayer sheet. Accordingly, there is no likelihood that the projections are deformed by being caught in the interlayer sheet when the chained terminals are dispensed from the reel.
Preferably, the carrier is formed with one or more protecting portions. The protecting portions are dimensioned to contact the interlayer sheet when the chained terminals are wound around the reel, thereby keeping the interlayer sheet and the terminal fitting pieces substantially separated from each other. Thus the projection portions contact the interlayer sheet as the interlayer sheet is separating from the terminal fitting pieces of the chained terminals that are being dispensed from the reel.
With the chained terminals wound around the reel, the protecting portions project in radial directions while being in contact with the interlayer sheet. Accordingly, the radial intervals of the respective layers of the chained terminals is held at a predetermined distance or longer. This keeps the terminal fitting pieces and the interlayer sheet, which depart from each other when the chained terminals are dispensed, separated from each other, and therefore securely prevents the projections from sticking into the interlayer sheet.
Most preferably, the terminal fitting piece is connected to the carrier via a covering portion that is configured to substantially cover or close an opening of the terminal fitting piece after its separation from the carrier.
According to the invention, there is further provided a method for forming or producing chained terminals according to the invention. The method comprises stamping a metal plate for forming a plurality of planar terminal fitting pieces projecting from a lateral side of a long carrier. The method continues by bending the terminal fitting pieces to form connection projections that projecting therefrom for connecting the terminal fitting pieces to an external device. The bending step is carried out such that the terminal fitting pieces are arranged with respect to the carrier in such an orientation that the connection projections project in directions substantially parallel to or substantially lying in a plane of the carrier.
According to the invention, there is further provided a method for forming chained terminals, comprising stamping a metal plate for forming a plurality of substantially planar terminal fittings that project from a carrier, in particular from the lateral side of a long strip or a plate. The method continues by bending the terminal fitting pieces, and providing the carrier with one or more protecting portions that project therefrom in a direction at an angle different from 0xc2x0 and 180xc2x0, preferably substantially normal to the carrier. A projecting distance of the protecting portions in a direction normal to the plane of the carrier is substantially larger than a projecting distance of the corresponding or adjacent terminal fitting piece.
Preferably, the method further comprises the step of winding the chained terminals around a reel with an interlayer sheet laid between adjacent layers of the chained terminals. Additionally the terminal fitting pieces are bent from the carrier in such an orientation that the connection projections of the terminal fitting pieces project substantially normal to radial directions of the reel.
The invention further relates to a chained terminal assembly, in which chained terminals according to the invention are wound on a reel with one or more interlayer sheets arranged or laid between adjacent layers of the chained terminals.
These and other objects, features and advantages of the present invention will become more apparent upon a reading of the following detailed description and accompanying drawings.